Changes of CBS expression in brain following ischemia and reperfusion of limbs / 中国病理生理杂志

ABSTRACT

AIM:To detect the changes of cystathionine β-synthase (CBS) expression in the brain following ischemia-reperfusion of hind limbs in the rats and to elucidate their significance .METHODS:Hind limb ischemia was in-duced by clamping infrarenal aorta with a microvascular clip and brain injury was made by following reperfusion .The brain tissue was obtained from the animals subjected to sham operation , 4 h of ischemia without reperfusion and 3 h, 6 h, 12 h, 24 h of reperfusion following 4 h of ischemia .The expression of CBS at mRNA and protein levels was measured at different time points by reverse transcription-polymerase chain reaction ( RT-PCR) and Western blotting .The CBS activity and hy-drogen sulfide ( H2 S) concentration in the brain were determined by a universal microplate reader .The observation of path-ologic changes of the brain was made following the inhibition of CBS by hydroxylamine .RESULTS:The relative expression of CBS at mRNA and protein levels in IR group significantly increased compared with sham group .It reached a peak at 12 h (P0.05).This time course correlated with increased CBS activity and H2 S concentration .No statistically significant difference in the above indexes between sham operation group and ischemia group was observed (P>0.05).Inhibition of CBS activity induced more severe brain injury in IR group .CONCLUSION:Up-regulation of CBS/H2 S pathway is involved in the protection for neurons during the ischemia-reperfusion of hind limbs .